Governor for pressure-fluid-operated tools



Nov. 22, 1927. 1,650,048

E. H. SHAFF eovsnnonmn PRESSURE FLUID ormmsn TOOLS Filed Feb. 5. 192a Patented Nov. 22, 1927 UNITED STATES ERNEST H. sHAEEoE GR ND HAVEN, MICHIGAN, Assrenon r WILLIAM KELLER; Inc, or GRAND HAVEN, MICHIGAN, A CORPORATION OF MICHIGAN.

GovEnNoE FOR PRESSUREJLtIID-OPERATED 'roons.

Application filed February More particularly the invention relates to a governor adapted to be inserted in the pressure fluid supply line to 'governautomatically the flow of pressure fluid to a tool such as a portable drill, grinder, -etc., in accordance with the load demands on the tool.

It is the general object of the invention to providea new and improved governor of the type which normally will pass a small quantity of pressure fluid to operate the tool at an idling speed and which, as the load on the tool increases, will pass automatically, increasing quantities of pressure fluid to the 7 tool.

It is another object of the invention to provide such a governor of lmproved and simplified construction and adapted to be manufactured at a low cost.

It is a further object of the invention to provide such a governor incorporating a pressure fluid actuated valve and means extending externally of the governor casing to permit adjustment of the normal position of the valve.

Further objects and advantages of -my' invention will be understoodfrom the following detailed description taken in connection with the accompanylng draw ngs, in

which,

Figure 1 1s a longitudinal central section of one form of the invention.

Fig. 2 is a central section of the member forming the valve seat.

Fig. 3 is an end View thereof.

Figs. 4 and 5 are views of-the pressure responsive member.

Referring particularly to Fig. 1 in the drawings, the invention in the form selected for purposes of disclosure embodies'a tubular casing comprising sections 1 and 2 secured together in longitudinal alinement as by means of the interengaging screwthreaded portions 3 and 4. Section 1 is preferably provided with an internally screw-threaded portion 5 adapted to engage a pressure fluid supply line (not shown), and section 2 has external threads 6 to permit ready coupling to a pressure fluid operated tool. Thus section 1 is adapted to form the intake end of the device and section 2 forms a back pressure chamber 7.

Disposed transversely within the casing is a circular member 8 herein shown clamped between an annular shoulder 9 on the section Y supply of 5, 1926. Serial No. 86,146.

section 1. 'This member has acup-like'projection 10' extending into the chamber'7,

opposite sides 11 of the projecting portion being parallel and having apertures or ports 12 therein to permitpressure fluid to pass through the casing.

Fitting slidably over this cup-like projection is a U-shaped valve 13, the leg portions of which are adapted to be guided by said projection 10' to control said ports. This valve is carried on one end of a hollow metaltube 14 of the Bourdo'n type having an elliptical cross section, which is sealed at both ends and normally of C shape (reversed as shown in Figs. 1 and 5). The opposite end of this tube is mounted on the casing section 2 ;tor adjustment transversely of the casing, the preferred mounting being herein shown as comprising a cylindrical pin 15 fitting snugly in a hole 16 through the casing and having the tube 14 secured rigidly to its inner end 17. "A nut 18 engaging a screw-threadedportion 19. of the pin 15 externally of the casing is provided for purposes of adjusting the normal position of the valve 13 with respect to the ports 12, a spring 20 being inter osed between the tube 14 and the inner wal of the casing to assist in such adjustment.

Assuming the intake end 1 connected to a pressure fluid and the'endJQ connected to a pressure fluid operated tool, such as a pneumatic drill,- the valve 13 is ad justed by means of the nut 18' to'pass normally a small quantity of pressure fluid through the casing sufficient to operate the tool at a running light or idl1ng-speed.'

Under such conditions the backpressure on the tool side of the valve 13 is low. "If then, a load be applied to the tool the tool tends to slow down and the backpressure in the chamber 7 increases. The characteristic of the tube 14 is such that upon being subjected externally to increased pressure the ends of the tube draw towards each other. It is therefore apparent that upon such increase in pressure in the chamber 7 the free end of the tube carrying the valve 13 moves vertically (as viewed in the drawings) to uncover the ports 12 and permits increased quantities of pressure fluid to flow to the tool. The movement of the valve and, therefore, the flow of pressure fluid will vary with the back pressure to govern automatically the admission of the pressure fluid in accordance with the load on the tool.

It Will also be apparent that the valve 13 is balanced or floating in nature in that it does not close against or with the live pressure fluid. As it is not necessary that the valve have an air tight fit against the ,valve seats 11, any leakage being consumed in operating the tool, the valve is preferably constructed to slide freely thereon. Therefore, the valve is not apt to stick as is experienced in air tight valves because of accumulations of foreign matter. The device is of asimplitied construction, the member 8 being readily removable upon disengagement of the casing sections and the valve being adapted for convenient adjustment from Without the casing.

I claim as my invention:

1. A governor of the character described comprising, in combination, a hollow cylindrical casing, a transverse Wall in said casing having a cup-like projection With opposed apertures therein, a U-shaped valve adapted to straddle said projection and close said apertures, pressure fluid responsive means to operate said valve comprising .a Bourdon tubesealed at both ends, and means to adjust said valve comprising a slidable member supporting one end of said tube and extending transversely through the casing Wall and a screw-threaded device externally ot the casing engaging said member.

2. A governor of the character described comprising, in combination, a tubular casing, a disk across said casing having a cup" shaped portion With opposedopenings therein adapted to permit pressure fluid to pass through said casing, a Bourdon tube sealed at both ends, a U-shaped valve carried on one end of said tube,isaid valve fitting over said cup-shaped portion to be guided thereby and to control the flow of pressure fluid through said openings, and means supporting the opposite end of said tube on the easing.

3. A governor of the character described comprising, in combination, a. holloW cylindrical casing, a transverse Wall in said casing having means defining a pair of opposed valve ports therein, a U-shaped valve adapted to slida'bly engage said means and control said ports, pressure fluid responsive 7 means to operate said valve comprising a holloiv metal tube sealed at both ends and normally C-shape, and means to support said tube for adjustment transversely of the casing.

4. A governor of the character described comprising, in combination, a tubular casing, a transverse wall in said casing having a cup-like projectionvvith a side vvall port therein defining a pressure fluid passage through said casing, a valve slidably engaging said projection to control theflovv of pressure fluid through saidport, and a Bourdon tube sealed at both ends, carrying said valve member on' one end and-having its other end mounted for adjustment transversely of the casing.

5. A governor of the character described comprising, in combination, a casing, a transverse Wall in said casing having a cuplike projection with a. port therein defining a pressure fluid passage through said casing, a valve slidably engaging said projection to control the, flow of pressure fluid through said port, a tubular metallic device sealed at both ends, carrying said valve member on one end and having its other end mounted for adjustment transversely ofthe casing, and means externally of the casing to vary said adjustment.

6. A governor of the character described,

having, in combination, a tubular casing comprising two sections detachably joined end to end and having a pressure fluid passage therethrough, means clamped between the adjacent ends of said sections forming a port defining a portion of said passage, 'a valve slidably engaging said, means and adapted to control the flow ofpressure fluid through said passage, and a pressure responsive metal tube normally C-shape and having one end thereof mounted on said casing adjustably with respect to said port, said tube carrying said valve on its free end.

In testimony whereof, I have hereunto aflixed my signature.

ERNEST H. SHAFF. 

